Locomotive-furnace



G. S. GRIGGS.

Steam-Boiler Furnace.

No. 18,888. Patend nec. 15, 1857.

UNITED STATES PATENT OFFICE.

GEO. S. GRIGGS, OF ROXBURY, MASSACHUSETTS, ASSIGNOR TO HIMSELF, AND WM. A. BULLARD, OF DEDHAM, MASSACHUSETTS.

LOCOMOTIVE-FURNACE.

Specification of Letters Patent No.

To all whom t may concern.'

Be it known that I, GEO. S. Cruces, of Roxbury, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Furnaces for Coal-Burning Locomotives, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is a front view of the furnace; Fig. 2, a similar View, the front being removed to show the parts within; Fig. 3, a longitudinal vertical section through the same.

The great obstacle to the combustion of smoke and gases thrown off from anthracite and bituminous coal within a locomotive or other steam boiler, results from the difficulty of maintaining these products at a sufriciently high temperature to insure their perfect combustion where the furnace is entirely surrounded by water space.

To obviate this difficulty and to insure the combustion of these gases is the obj ect of my present invention which consists in the employment of a fire brick arch immediately beneath and in front of the tube plate, which soon becoming intensely hot raises the temperature of the smoke and gases as they pass over it to such a degree as entirely and effectually to consume them as will now be more particularly explained.

In the said drawings A is the fire door, B the grate, C the tube plate, D an arch of fire brick springing from the sides of the furnace at f, and crowning about 5 inches more or less in the center. At the springing lines f the arch is supported by angle irons secured by hollow bolts. This arch may be built solid or with openings e left in it to permit the passage of the flame and increase the area of the heated surface. The arch may extend from one third to one half the distance from the tube sheet to the fire door, and its center line or crown may be hori- Zontal or inclined upward.

The operation is as follows, the coal being thrown in at the door A, falls at g', when a preliminary combustion or coking takes place. From this point it is thrown forward beneath the arch by the Stoker, where the combustion is completed. When thus operated, the arch D becomes intensely heated by the flame rising from the fire beneath.

18,883, dated December 15, 1857.

This flame together with the highly heated air which enters through the grates, becomes mixed as it rises with the g-ases from the fire at g, and the two are consumed as they pass over the heated arch near the center of the fire box. The advantages of this arrangement are many. 1st. Any ordinary wood engine may at short notice and at a very trifhng expense be altered so as to burn with economy either anthracite or bituminous coal. 2d. The arch prevents the entrance of cinders and ashes into the tubes. 3d. The heat is distributed more evenly over the whole interior surface of the furnace. 4th. The lues are protected from the intense heat to which they are exposed when the combustion takes place immediately front of the tube sheet. 5th. The brick arch not being connected with the sides of the boiler, the latter is not strained or injured by unequal contraction or expansion. 6th. The fire brickubecomes so intensely heated unlike the balance of the interior of the furnace, as to consume all gases and smoke that pass over or in Contact with it, this very combustion assisting to maintain the heat in the arch.

I do not claim placing ahollow or water space fire bridge within a locomotive or other furnace as such bridge in whatever position or under whatever arrangement it may be used will not accomplish the end which I have in view. Neither do I claim the use of fire bridges of fire brick either with or without perforations, except when such bridges are arranged substantially as herein set forth.

That I do claim however as my invention and desire to secure by Letters Patent is- The within described arrangement of a re brick arch or shelf attached to the rear of the furnace and extending horizontally or nearly so, beneath and in front of the tube sheet, and over the re toward the fire door in such a manner as to form a combustion chamber immediately in front of the tube sheet in which the smoke and gases after passing over the heated surface of the bridge, are consumed as set forth.

GEORGE S. GRIGGS.

Witnesses:

SAM. COOPER, Trios. R. RoAoH. 

